M1 can adapt to pretty much any MAME romset from the last several years. I'm not familiar with exactly which ROMs Mame4All wants; it's based on MAME 0.36 from the year 2000 (remember when that sounded futuristic?) with some various hacks. I hope it doesn't actually use ROMs from 0.36 though ;-)

Heres an up-to-date apk. I lost my key like a year ago so you might have to uninstall the version you have before you install this. This isn't really any different than the Google Play version except 1) it has an icon now, thanks to NFG 2) it targets 4.2.2 and might look a little different now but should still run on older phones.

Will you be replacing the Stop button with a Restart Song button like the desktop M1 versions have? Since Stop just crashes the app, and Restart Song has a useful purpose at least, it'd make a good replacement button.